一种单级原边控制LED驱动器设计

摘要

设计了一种单级原边控制LED驱动器.采用反激式开关电源结构,控制器由乘法器,功率管开通控制,过零检测/副边导通检测,峰值电流比较器,RS触发器,逻辑控制以及预驱动等模块电路构成.利用这个控制器设计了LED驱动器.通过测试,实现了高低压交流输入情况下输出电流相同,高功率因数,低总谐波失真；这个电路外围简单,降低了电路成本,PCB板空间很小,有利于产品小型化；适合交流供电,有功率因数调整要求和隔离要求的LED驱动.%A single-stage primary side LED driver is presented. The driver uses flyback switching power supply topology. The controller includes a multiplier unit, a power-switch on control unit, a zero-crossing detection/ secondary side conduction detection unit,a peak-current comparator unit,a RS flip-flop unit,a logic control unit and a power-switch pre-drivcr unit. Using this controller, a LED driver circuit is designed. After testing the circuit, almost same output current in different AC input is derived. At the same time.it has high power factor correction and low total harmonic distortion. The circuit is simple for LED constant current driver by using the driver circuit. It decreases the total cost for LED driver,and decreases the PCB area. It is conducive to miniaturization. It is suitable for the LED driver which is AC power supply,power factor adjustment request and isolation requirements.